I know this is a dumb question even before I ask but I cannot figure it out: why do only some of the games on chessgames.com end in a final move that is actually checkmate, while others don't? On this one for example the final move says "Black to move" and you can move them around to get to a checkmate yourself...did they just shake hands and not play the final couple moves out?
Yes, it is common for high level players to just shake hands and resign, when they know the position is lost and their opponents certainly will checkmate them
Unless your opponent has just executed such a brilliant set of moves that they deserve the satisfaction of actually finishing the sequence and delivering checkmate.
As others have mentioned, it is extremely rare for chess grandmasters to play until checkmate. In many cases, when the game is clearly lost, it can even be seen as disrespectful, and a waste of your opponent's time.
